diff --git a/src/edutap/wallet_google/api.py b/src/edutap/wallet_google/api.py
index 4150e03..cd894e9 100644
--- a/src/edutap/wallet_google/api.py
+++ b/src/edutap/wallet_google/api.py
@@ -376,13 +376,19 @@ def save_link(
             if isinstance(obj, dict) and "id" in obj and len(obj.keys()) <= 2:
                 obj = GoogleWalletObjectWithClassReference.model_validate(obj)
             if isinstance(obj, GoogleWalletObjectWithClassReference):
-                payload[name].append(obj.model_dump(exclude_none=True, mode="json"))
+                payload[name].append(
+                    obj.model_dump_json(
+                        exclude_none=True,
+                        exclude_unset=True,
+                        exclude_defaults=True,
+                    )
+                )
                 continue
 
             # otherwise it must be a registered model
             model = lookup_model_by_plural_name(name)
             obj = _validate_data(model, obj)
-            obj_json = obj.model_dump(exclude_none=True, mode="json")
+            obj_json = obj.model_dump_json(exclude_none=True)
             payload[name].append(obj_json)
     claims = {
         "iat": "",
@@ -394,9 +400,9 @@ def save_link(
     }
     signer = crypt.RSASigner.from_service_account_file(session_manager.credentials_file)
     jwt_string = jwt.encode(signer, claims).decode("utf-8")
-    logger.debug(
-        "JWT-Length: %d, is less than recommenden 1800: %s",
+    logger.warning(
+        "JWT-Length: %d, is larger than recommenden 1800: %s",
         len(jwt_string),
-        len(jwt_string) <= 1800,
+        len(jwt_string) >= 1800,
     )
     return f"{session_manager.save_url}/{jwt_string}"
diff --git a/src/edutap/wallet_google/modelbase.py b/src/edutap/wallet_google/modelbase.py
index 3d0939b..d787b71 100644
--- a/src/edutap/wallet_google/modelbase.py
+++ b/src/edutap/wallet_google/modelbase.py
@@ -18,27 +18,6 @@
 from pydantic import Field
 
 
-# class GoogleWalletModel(BaseModel):
-#     """
-#     Base model for all Google Wallet models.
-#     """
-
-#     model_config = ConfigDict(
-#         extra="forbid",
-#         # extra="ignore",
-#         use_enum_values=True,
-#     )
-
-
-# class GoogleWalletWithIdModel(GoogleWalletModel):
-#     """
-#     Base model for Google Wallet models with an identifier.
-#     """
-
-#     kind: str | None = Field(description="deprecated", exclude=True, default=None)
-#     id: str
-
-
 class GoogleWalletClassModel(GoogleWalletWithIdModel):
     """
     Base model for all Google Wallet Class models.
diff --git a/src/edutap/wallet_google/models/jwt.py b/src/edutap/wallet_google/models/jwt.py
index 1a7c268..a9d5c95 100644
--- a/src/edutap/wallet_google/models/jwt.py
+++ b/src/edutap/wallet_google/models/jwt.py
@@ -19,7 +19,8 @@
 )
 class JwtResource(GoogleWalletModel):
     """
-    see: https://developers.google.com/wallet/tickets/events/rest/v1/jwt
+    see: https://developers.google.com/wallet/reference/rest/v1/jwt
+         https://developers.google.com/wallet/tickets/events/rest/v1/jwt
          https://developers.google.com/wallet/generic/web/javascript-button#google-pay-api-for-passes-jwt
     """
 
@@ -28,7 +29,8 @@ class JwtResource(GoogleWalletModel):
 
 class Resources(GoogleWalletModel):
     """
-    see: https://developers.google.com/wallet/tickets/events/rest/v1/jwt/insert#resources
+    see: https://developers.google.com/wallet/reference/rest/v1/jwt/insert
+         https://developers.google.com/wallet/tickets/events/rest/v1/jwt/insert#resources
     """
 
     # the documentation says nothing about GenericClass/Object here
diff --git a/src/edutap/wallet_google/models/retail.py b/src/edutap/wallet_google/models/retail.py
index 23b9fdc..eed6575 100644
--- a/src/edutap/wallet_google/models/retail.py
+++ b/src/edutap/wallet_google/models/retail.py
@@ -25,8 +25,8 @@
 from .primitives.enums import ViewUnlockRequirement
 from .primitives.localized_string import LocalizedString
 from .primitives.location import LatLongPoint
+from .primitives.message import Message
 from .primitives.money import Money
-from .primitives.notification import Message
 from .primitives.retail import DiscoverableProgram
 from .primitives.review import Review
 from pydantic import BaseModel
diff --git a/src/edutap/wallet_google/models/tickets_and_transit.py b/src/edutap/wallet_google/models/tickets_and_transit.py
index 66df63e..b751aa2 100644
--- a/src/edutap/wallet_google/models/tickets_and_transit.py
+++ b/src/edutap/wallet_google/models/tickets_and_transit.py
@@ -57,6 +57,17 @@ class EventDateTime(GoogleWalletWithKindModel):
     customDoorsOpenLabel: LocalizedString | None = None
 
 
+class EventSeat(BaseModel):
+    seat: LocalizedString | None = None
+    row: LocalizedString | None = None
+    section: LocalizedString | None = None
+    gate: LocalizedString | None = None
+
+
+class EventReservationInfo(BaseModel):
+    confirmationCode: str | None = None
+
+
 @register_model(
     "EventTicketClass",
     url_part="eventTicketClass",
@@ -98,17 +109,6 @@ class EventTicketClass(GoogleWalletClassModel, GoogleWalletMessageable):
     countryCode: str | None = None
 
 
-class EventSeat(BaseModel):
-    seat: LocalizedString | None = None
-    row: LocalizedString | None = None
-    section: LocalizedString | None = None
-    gate: LocalizedString | None = None
-
-
-class EventReservationInfo(BaseModel):
-    confirmationCode: str | None = None
-
-
 @register_model(
     "EventTicketObject",
     url_part="eventTicketObject",